Return multiple values

What

Python provides nice syntax for ‘returning multiple values’. In reality, only one value is returned: a tuple containing all the specified values.

Python does not allow returning multiple values but its syntax gives the illusion of doing so:

• Python can return a tuple (parentheses optional)
• Syntax for multiple assignments makes unpacking the tuple trivial

Why

By ‘returning multiple values’ and using Python’s convenient syntax, you group return values without using or defining a complex data structure. This can make your code more readable.

Examples

Return an explicit tuple

We could similarly return a list or dictionary.

def division(dividend, divisor):
    quotient = dividend // divisor
    remainder = dividend % divisor
    return (quotient, remainder)
 
results = division(23, 5)  # results = (4, 3)
q, r = division(19, 2)  # q = 9, r = 1

Return an implicit tuple

Python does not require parentheses around the grouped values being returned, it groups them in a tuple automatically.

def division(dividend, divisor):
    quotient = dividend // divisor
    remainder = dividend % divisor
    return quotient, remainder
 
results = division(23, 5)  # results = (4, 3)
q, r = division(19, 2)  # q = 9, r = 1

Things you should know

Grouping multiple return values in a tuple is not always sensible. Just because you can do it, doesn’t mean that you should.

When you start returning more than a couple of values, it’s probably time to think about using a more intentional data structure (e.g., a dictionary or a custom object) to better organise your data.